Field of the Disclosure
Embodiments of the disclosure generally relate to thermally treating substrates, such as semiconductor substrates.
Description of the Related Art
Rapid thermal processing (RTP) chambers commonly utilize lamps to provide thermal energy to a substrate. The lamps are arranged in lamp heads, and the energy from the lamps is directed towards a substrate or substrate support within a processing chamber to provide thermal energy to the substrate. The radiant energy from the lamps overlaps the substrate or the substrate support in uneven or non-uniform patterns, due to, for example, geometry of the lamp arrangement, chamber or lamp features, or the geometry of the field emitted by each lamp. Moreover, the irradiance patterns of each individual lamp are often not uniform. For example, some lamps may deliver more thermal energy to a central portion of a respective irradiance pattern compared to an outer portion of the irradiance pattern. The uneven irradiance results in uneven heating of the substrate, adversely affecting substrate uniformity.
Therefore, there is a need for more uniform irradiance of substrates.